1. Field of the Invention
The present invention relates to a safety apparatus for a brake of a vehicle, and more particularly a safety apparatus for a brake of a vehicle with an independent brake safety apparatus, in which an auxiliary vacuum pump is driven to normally operate a brake when an intake manifold does not maintain a vacuum due to a sudden acceleration or a stopping of an engine because an ECU, a throttle valve and wire, which are parts relating to the sudden acceleration, malfunction due to a weak durability of the parts caused by impact or due to an introduction of rain water caused by a weak durability and a defect of an exterior material, in which a supply of electric power to a fuel motor is blocked so as to stop an operation of an engine when the brake is abnormally operated because a brake booster is lack of vacuum due to a deterioration of the auxiliary vacuum pump, in which the brake normally operates to prevent an accident even though the sudden acceleration occurs or the operation of the engine is stopped in driving, and in which it is possible to prevent a fade or vapor lock of the brake which may be caused by a lack of a vacuum as the brake is continuously operated when a diesel vehicle is driven on a downhill road.
2. Description of the Prior Art
Generally, an automatic transmission means a transmission gear for automatically changing a speed ratio of wheel to an engine, and a braking system.
The brake system for stopping a driving vehicle is a hydraulic braking system which performs a brake using a hydraulic pressure, and includes a braking pedal, a booster, a master cylinder, a proportional valve, front and rear brake assembly and a brake rotor.
Further, in the brake system, when a driver pushes a brake pedal in order to stop a vehicle, the brake pedal firstly increases force due to its kinematic structure and the booster secondly increases the force. Continuously, the master cylinder converts the force into a hydraulic pressure.
Here, the hydraulic pressure is applied to the brake assembly of each wheel through a brake tube and the proportional valve, and in turn the hydraulic pressure applied to the brake assembly is converted into force again to push a brake pad, thereby applying pressure to the rotating rotor so as to brake the rotor.
A general type of brake system is a combination of a hydraulic torque converter for changing and transmitting a rotation speed and a rotation force by applying a character of fluid, and 2 to 4 speed mechanical transmission which is automatically operated by a hydraulic pressure.
However, in the brake system, the booster amplifies force, which is generated when the driver pushes the brake pedal, by using a negative pressure of an intake manifold according to an operation of an engine. When revolutions of the engine rapidly increase so that the negative pressure of the intake manifold is significantly lowered, the negative pressure applied to the booster is also lowered due to the lowered negative pressure of the intake manifold. Accordingly, there is a problem in that the booster fails to amplify a pressure therein so that a vehicle cannot be stopped even though the driver pushes the brake pedal to increase the hydraulic pressure in order to stop the vehicle.
On the other hand, when using an automatic transmission, since an initial speed of a vehicle is determined based on a position of a transmission gear of the transmission, the vehicle may start at a rapid speed so as to cause a collision accident.
Further, an Electronic Control System (ECU) may make a throttle body malfunction, thereby lowering the negative pressure of the intake manifold. In addition, the ECU may fail to control an ignition control apparatus to make ignition timing irregular, thereby lowering the negative pressure of the intake manifold.